The present invention relates to pins, tacks and other instruments used to attach articles to bulletin boards and the like and, more particularly, to tacks adapted to be attached to a bulletin board or to each other in a stacked relation.
A problem inherent with all bulletin boards and other structures performing a similar function is that they lack means for the orderly display of notices which are attached to them, with the result that such bulletin boards often become cluttered with notices, making it difficult to find a particular notice. In addition, there is no present device which permits related notices to be grouped together on a bulletin board.
There are many types of tacks designed specifically for use with bulletin boards. For example, the Hayashi U.S. Pat. No. 3,121,365 and Miley U.S. Pat. No. 1,189,604 disclose tacks having heads with resilient members for gripping sheets of material to be attached to the bulletin board. These tacks possess an advantage over prior art tacks in that they need not be removed from the bulletin board to which they are attached, then reattached to pierce the sheet material to be mounted. Rather, the resilient member is adjusted to clamp the sheet to be mounted on the bulletin board, and can be readjusted to release the sheet when the sheet is no longer needed.
However, a disadvantage with such types of tacks is that they do not sufficiently eliminate the tendency of such bulletin boards to become cluttered with sheets of messages and notices. Furthermore, they do not facilitate the grouping of related notices on a board. Accordingly, there is a need for a tack system which promotes the orderly display of notices on bulletin boards and the like and which facilitates the grouping of related notices.